Fig. 6
From: Evaluation of the effects of ascorbic acid on metabolism of human mesenchymal stem cells
Proposed mechanism of the effect of ascorbic acid on mesenchymal stem cells. A deficit of AsA in the culture medium decreases the activity of ascorbic acid-dependent enzymes including collagen prolyl 3-hydroxylase, collagen prolyl 4-hydroxylase, HIF-prolyl hydroxylase, and ten-eleven translocation DNA demethylase. Collagen prolyl 3-hydroxylase and collagen prolyl 4-hydroxylases are crucial for the formation of the triple helix. HIF-prolyl hydroxylase catalyzes the posttranslational formation of 4-hydroxyproline in HIF1α proteins. Tet has been shown to convert the covalent epigenetic mark 5-methylcytosine to 5-hydroxymethylcytosine in DNA